This systematic review synthesizes 12 cadaveric biomechanical studies evaluating surgical techniques to prevent PJK and PJF after long-segment posterior fusion for adult spinal deformity. Techniques assessed include semi-rigid junctional fixation (suture loops, tethers, sublaminar tape, hooks) and prophylactic vertebroplasty. No meta-analysis was possible due to protocol heterogeneity across studies.
PJK complicates 20-40% of long-segment ASD fusions, and nearly half of patients who progress to PJF end up back in the OR. Despite widespread use of semi-rigid junctional techniques, the biomechanical rationale for specific choices has been scattered across heterogeneous cadaveric studies with no prior synthesis.
When planning a long-segment ASD fusion in an osteopenic patient, favor sublaminar tape or pretensioned tether fixation at UIV+1 (and UIV+2 for two-level constructs) over transverse process hooks or rod-stiffness modifications. Two-level sublaminar tape produces the broadest biomechanical effect across all planes. Any tether or loop construct must be pretensioned with a tensioning device or caudal crosslink distraction — hand-tied constructs provide zero biomechanical protection.
For patients at high fracture risk (low BMD, osteoporosis), two-level prophylactic vertebroplasty at UIV and UIV+1 addresses compressive failure through a separate mechanism and can be added to semi-rigid fixation without redundancy.
The key limitation: no study has defined what ROM transition is actually "optimal" clinically, so even the best-performing constructs may be achieving near-rigid fixation rather than a true gradual transition.
This systematic review synthesizes 12 cadaveric biomechanical studies evaluating surgical techniques to prevent PJK and PJF after long-segment posterior fusion for adult spinal deformity. Techniques assessed include semi-rigid junctional fixation (suture loops, tethers, sublaminar tape, hooks) and prophylactic vertebroplasty. No meta-analysis was possible due to protocol heterogeneity across studies.
PJK complicates 20-40% of long-segment ASD fusions, and nearly half of patients who progress to PJF end up back in the OR. Despite widespread use of semi-rigid junctional techniques, the biomechanical rationale for specific choices has been scattered across heterogeneous cadaveric studies with no prior synthesis.
When planning a long-segment ASD fusion in an osteopenic patient, favor sublaminar tape or pretensioned tether fixation at UIV+1 (and UIV+2 for two-level constructs) over transverse process hooks or rod-stiffness modifications. Two-level sublaminar tape produces the broadest biomechanical effect across all planes. Any tether or loop construct must be pretensioned with a tensioning device or caudal crosslink distraction — hand-tied constructs provide zero biomechanical protection.
For patients at high fracture risk (low BMD, osteoporosis), two-level prophylactic vertebroplasty at UIV and UIV+1 addresses compressive failure through a separate mechanism and can be added to semi-rigid fixation without redundancy.
The key limitation: no study has defined what ROM transition is actually "optimal" clinically, so even the best-performing constructs may be achieving near-rigid fixation rather than a true gradual transition.